Growing up in a family of entomologists, bankruptcy lawyer Mark Sterling was always interested in moths. He could never quite “kick the habit” despite being busy rescuing troubled businesses. Now, at 61, the retired Briton is back to chasing moths-and his pursuit has brought him to India.

Sterling is an (unpaid) scientific associate at the Natural History Museum, London. His current project is to look at certain material in the museum since British entomologist Edward Meyrick’s time – which has so far remained uncurated and undescribed – on the basis of morphological analysis and DNA sequencing.

“The work that I am doing at the moment involves a group of which 25 species were described between 1894 and 1934,” Sterling said. “Almost all of them were described by Meyrick, in almost all cases in India and Sri Lanka – except for a pest species described by another scientist from Japan.”

Butterflies and moths make up the order of insects called Lepidoptera. Xyloryctidae is a family of moths contained within the superfamily Gelechioidea, described by Edward Meyrick in 1890.

“There’s been very little work done on that group [Metathrinca] since,” Sterling told Mongabay. “The work so far shows that this is actually a very large group that occurs from New Guinea to Japan, including most of southern Asia, India, and China.”

A collection of Metathrinca group specimens (small moths) at the NHM. Credit: Mark Sterling/Mongabay

Searching

One aim of his Kolkata visit, said Sterling, is to find some modern material (specimens) from India.

“There is no recorded specimen from India of any Metathrinca group moth since 1934,” he said. “I am hoping to find fresh specimens because the historic Indian specimens are too old to produce viable DNA sequences at a realistic cost, if at all. I am hoping to find live specimens from India which will allow me to sequence modern materials.”

Sterling observed it is impossible to know exactly what type of habitats the old Indian materials were collected from. “All we know from their data is that they were collected from Meghalaya/the Khasi Hills/Shillong but from this, we can assume that they are classical northeast Indian hill and forest species,” he said.

However, the British NHM also has species from southern Asia, in the 1970s and 1980s, which are a mixture of hill and forest species including a number of mangrove forest species, so Sterling said he is hoping to find some modern Indian specimens at the forest site in Dalma and the mangrove forest site in the Sunderbans.

“Whether I find any is largely a matter of luck as I have no real insights into the exact sorts of habitats in which these species occur,” said Sterling, describing what he calls a hit and miss approach. “So I will be putting out light traps at night, as the males, in particular, are attracted to light. I am hoping I may find a few females. I will be putting out my lights hoping for the best but, if I don’t find at least some specimens on this trip, I will be disappointed, given the diversity of the group and the richness of the Indian species. If I find the material I will need to collaborate with scientists in India in order to sequence and/or describe them and will undoubtedly need to find an excuse to come back to Kolkata in order to find further materials.”

Sterling said he is keen on examining the genetic difference between the described Indian species and the species he is describing from the rest of Asia.

“If I can find fresh Indian specimens which are morphologically identical to already described Indian species I will be able to obtain sequences from the fresh specimens and form a view as to the genetic divergence of the Indian species from the species from other parts of Asia,” he said.

Contributing to knowledge

Sterling acknowledged that discovering and describing moth species may not be a huge benefit to mankind, but knowledge of biodiversity is critically important.

“It’s not something which will make the difference between economic riches for large corporations and it is not something which will improve agriculture so I can’t claim it will be a huge benefit to mankind,” argued Sterling. “But knowledge of biodiversity is critically important. Biodiversity in itself should be regarded as an important resource in its own right and we will be contributing to the knowledge of biodiversity.”

He also stressed on balancing conservation with real needs.

“We need to conserve biodiversity but that can’t be the only aim of the government; you have to balance conservation with very real needs of feeding a massive population,” elaborated Sterling. “You need to know how to conserve, what is most important to conserve, and how to do it and in order to do that as a starting point, you need to understand what the biodiversity is, and to understand the biodiversity you need to know what species are in a place.”

Focus on the lesser-studied small moths

Sterling grew up in England, Germany, and Belgium in a family of lepidopterists and has always been interested in moths and smaller moths because butterfly diversity in England is very low. “There are only 64 species of resident butterflies in England,” he said. “Moths are more of a challenge and interesting and smaller moths were not very well known when I was younger so they were an obvious area of interest.”

Unlike other family members, Sterling became a lawyer but always kept an interest in moths. “When I became a partner in my firm I was sent to Hong Kong to set up an Asian bankruptcy business so I started working on smaller moths of Asia in my spare time,” he recounted. “I never managed to kick the habit. Now that I am retired I can go back to the family passion.”

The older brother of well-known entomologist Phil Sterling, lead author of the acclaimed micro-moth guide The Field Guide to the Micro-moths of Great Britain and Ireland, Mark Sterling finds smaller moths challenging.

“Smaller moths are challenging because there are very few people working on them, compared to larger moths and even more so if compared to butterflies,” Mark Sterling noted. “For example, if I go out on the field somewhere in Hong Kong, Malaysia or North East India I will expect that 50% to 80% of the smaller moths I see will be undescribed species.”

Sterling says there could be at least 20,000 to 30,000 species of Lepidoptera waiting to be discovered only in India.

“In India, there are about 10,000 species of Lepidoptera described,” he said. “Published estimates range between a further 10,000 to 20,000 which are undiscovered. On the basis of old historical records in NHM on which I am working, I would have thought the 10,000 to 20,000 number is a significant underestimate so there could be at least 20,000 to 30,000 species [of Lepidoptera] only in India.”

But with a dearth of taxonomists, how do you get people to take an interest in conservation?

Sterling believes an appreciation of the natural environment and biodiversity should be an important part of everyday life. In some countries, this is beginning to happen. For example, in England, membership of the Royal Society for the Protection of Birds exceeds the aggregate membership of the three main British political parties. Appreciation of moths and butterflies should be an important and exciting recreational activity open to everyone, he emphasised.

“Seeing a rare beautiful butterfly or moth ought to be as exciting as watching [Indian cricketing legend] Sachin Tendulkar score a century,” observed Sterling. “The starting point is introducing people, children who want to do recreational activities in the evening, when they are not working, to the spectacular diversity of moths and butterflies.”

“If they are regarded as something to be treasured then research into them is going to be much easier to find funding so the starting point is educational and proselytization of natural resource as something which is there to be appreciated and enjoyed as a relaxation from what we do in our working lives,” Sterling signed-off.